1. Field of Invention
The present invention relates to women's undergarments, and particularly to women's undergarments including a ventilated crotch assembly.
2. Description of the Prior Art
There has been much written in the recent literature which suggests that for overall comfort and body benefit, the crotch assembly of women's undergarments should promote air circulation, be moisture absorbent, and permit the dissipation of body heat. This literature expresses the view that relatively non-porous nylon crotch linings in panties and pantyhose do not promote good hygiene and that feminine undergarments should have a soft, moisture absorbent crotch liner.
This view has created much interest, especially since many of the more popular types of women's panties are knitted of thermoplastic yarns such as nylon. The knit is relatively close, restricts air circulation and the nylon covers the crotch area of the wearer.
Many manufacturers have included cotton fabric in the crotch assembly. Oftentimes, this takes the form of an inner cotton linear against the outer shell or layer of thermoplastic yarn. Since the cotton liner is moisture absorbent, it will aid in drawing secretions away from the body and defuse them throughout the crotch area. While this may provide some improvement over an all nylon crotch assembly, the outer nylon shell is itself non-moisture absorbent and due to its relatively closed knit, still restricts air circulation.
Some manufacturers have sought to overcome this problem by eliminating the outer shell of nylon and providing only a single layer cotton crotch piece.
This approach, while eliminating the problemsome nylon outer layer, fails to recognize that a dual layer crotch construction is highly preferable in women's undergarments. Incontinence or vaginal discharge is not an unusual condition in women. By providing dual layers in the crotch construction there is an outer barrier liner which masks the possible staining or discoloration which may often occur during wear. Where there is only a single layer of material the masking advantages of the outer shell is lost. The panties become non-acceptable for use well before their useful life might otherwise expire. Yet, even with this disadvantage, where ventilation is sought, a single layer has been employed. This has recently taken the form of an openwork, mesh-like layer of material.
The mesh-like fabric has relatively large open areas of either a non-moisture absorbent thermoplastic yarn such as nylon or a moisture absorbent yarn such as cotton. While a greater degree of air circulation is potentially available due to the openwork nature of the material, the degree of masking against staining and/or discoloration is minimal. In addition, not only the undergarments but outer garments can be soiled as the relatively large open spaces permit body moisture to pass through the crotch layer. Even where the yarns employed have the potential for moisture absorption the relatively sparce surface area limits absorbency. There is also an aesthetic problem in that many women find such single layered open mesh arrangements undesirable for modesty reasons as there is a relatively high degree of body show-through.
While it might be supposed that the addition of a second barrier layer to the mesh-like material would overcome this deficiency, the addition of a thermoplastic layer is unsatisfactory. Moisture absorbency is not provided and air circulation is restricted. Surprisingly, the addition of a non-thermoplastic moisture absorbent outer layer, even one with a relatively high level of openness, may not in and of itself solve the problem. As hereinafter more fully set forth, where two non-thermoplastic layers of material are employed, even of a relatively openwork type, a heat retentive rather than a cooling effect can result.
While, at least one prior worker did appear to recognize that openings along may not be sufficient to provide ventilation and suggested a degree of flexibility to force air to the region, this has taken the form of a thin layer openwork elastic insert which covered but a part of the crotch and extended down the sides of the legs so that a bellows type effect would take place during wear. However, even in this teaching, the crotch still included major closed sections of close fitting fabric and but a thin ventilated channel was provided (See U.S. Pat. No. 1,106,310 to Kelly).
The present invention has solved these various problems. It provides a crotch assembly of two moisture absorbent, non-thermoplastic layers which overcomes the propensity for heat retention and which during wear provide an excellent level of air permeability; a high level of moisture absorbency; a high level of comfort; and an effective barrier arrangement for long wear life.